利用明亮孪生光束的鬼红外光谱

中文摘要 AI 辅助

频率关联光为无需直接在中红外（MIR）波段进行光谱探测的中红外光谱学提供了一条途径。此前的中红外鬼光谱学主要依赖低增益自发参量下转换（SPDC）及光子对符合测量，有限的光子通量将采集时间限制在一分钟以上。本文中，我们展示了利用高增益参量下转换（PDC）产生的明亮孪生光束实现的鬼红外光谱学。高增益PDC放大真空涨落，在每个泵浦脉冲中产生一对不同的频率关联随机光谱。这种脉冲分辨的随机发射与时间拉伸探测天然匹配，该探测方式记录每个脉冲对应的关联近红外电信信号光谱，而中红外闲频光则通过桶探测进行测量。因此，每个泵浦脉冲产生一对包含光谱分辨参考值及对应桶值的投影测量值。我们以毫秒级采集时间重构了结构化光学滤光片的透射光谱及液态苯在3.3μm附近的分子振动吸收光谱，结果与傅里叶变换红外光谱学吻合良好。与此前的中红外鬼光谱学演示相比，这将采集时间缩短了4至5个数量级。这些结果将鬼光谱学从基于符合的光子计数转变为高通量模拟关联光谱学，建立了由窄带半导体激光驱动的高速计算红外光谱学的实用架构。

英文摘要

Frequency-correlated light offers a route to mid-infrared (MIR) spectroscopy without direct spectral detection in the MIR. Previous MIR ghost spectroscopy has mainly relied on low-gain spontaneous parametric down-conversion (SPDC) and photon-pair coincidence measurements, where the limited photon flux has restricted acquisition times to longer than one minute. Here, we demonstrate ghost infrared spectroscopy using bright twin beams generated by high-gain parametric down-conversion (PDC). High-gain PDC amplifies vacuum fluctuations, producing a different pair of frequency-correlated random spectra in each pump pulse. This pulse-resolved stochastic emission is naturally matched to time-stretch detection, which records the spectrum of the correlated near-infrared telecom signal for every pulse, while the MIR idler is measured by bucket detection. Consequently, each pump pulse yields one paired projection measurement comprising a spectrally resolved reference and the corresponding bucket value. We reconstruct the transmission spectrum of a structured optical filter and the molecular vibrational absorption spectrum of liquid benzene near 3.3 um with millisecond-scale acquisition, in good agreement with Fourier-transform infrared spectroscopy. This reduces the acquisition time by four to five orders of magnitude compared with previous MIR ghost spectroscopy demonstrations. These results transform ghost spectroscopy from coincidence-based photon counting to high-flux analog correlation spectroscopy, establishing a practical architecture for high-speed computational infrared spectroscopy driven by a narrowband semiconductor laser.

发表机构

• The University of Tokyo（东京大学）
• RIKEN Center for Advanced Photonics, RIKEN（理化学研究所前沿光子学中心）

机构由 AI 辅助整理，请以论文原文为准。